"The Mystery of Liu Qingqing" tells the story of Liu Qingqing, the legitimate daughter of the prime minister's house, who was framed by her concubine Qiu Duoduo, and the whole family was wronged and beheaded. She narrowly escaped death under the protection of her loyal servant Liu Lei. Six years later, she disguised herself as a man and returned to the court as an "unparalleled counselor" to secretly plot revenge. During this period, she adopted Dabao, an orphan from the war, as her adopted brother, and formed an alliance with Zhang Lei, the minister of the Ministry of Justice, and Sun Lei, the commander of the Forbidden Army, and gradually exposed Qiu Duoduo's conspiracy to collude with foreign enemies. In the whirlpool of power and intrigue, Liu Qingqing and Liu Lei gradually fell in love with each other. They worked together to break the situation, and finally used thunderous means to overthrow Qiu Duoduo and restore the family's glory. The story combines the thrill of revenge with the protection of a sweet pet, showing the heroine's wisdom and courage in counterattacking from desperate situations, as well as the touching friendship of life and death in troubled times.